Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: September 17, 2005
Publication Date: February 1, 2005
Citation: Clements, C.D., Young, J.A. 2005. The use of goat grazing to biologically suppress perennial pepperweed [abstract]. Weed Science Society of America. 45:133. Technical Abstract: Perennial pepperweed (Lepidium latifolium), also known as tall whitetop, is a creeping rooted exotic weed that has infested riparian areas, native hay meadows and agronomic fields throughout the western United States. Perennial pepperweed is a highly invasive weed that causes management and economic problems through the loss of diversity and forage quality. The use of herbicides is the most common practice in the effort to control this invasive perennial weed, but in recent times there has been increasing discussion on the use of biologically suppressing this weed through sheep and goat grazing. We investigated the grazing of perennial pepperweed by goats during 1998 and 1999 in northwestern Nevada. Eight ¼ acre enclosures were constructed to monitor the utilization and effect of goat grazing on perennial pepperweed. Four of the enclosures were grazed and combined with various herbicidal treatments, while the remaining 4 enclosures were grazed throughout the summer and the seeded to a perennial grass. Heavy grazing of perennial pepperweed decreased herbage yield by 78%, yet did not significantly (P > 0.05) decrease the number of perennial pepperweed plants in the plots. The control of perennial pepperweed using the combined grazing with herbicidal treatments was not significant (P > 0.05) compared to the herbicidal treatments alone. Grazing perennial pepperweed as a control method followed by seeding was unsuccessful due to the fact that the sprouting perennial grass seedlings could not compete with the dense creeping rooted perennial pepperweed population. The use of the selectice herbicide 2,4-D during the flowering or budding stage (June) followed by fall seeding of the competitive perennial grass tall wheatgrass (Elytriia elongata) followed up by a low rate application of 2,4-D over the tall wheatgrass seedlings the next spring (May) was significantly (P < 0.05) more successful than those plots treated with goat grazing.